Whether they break rules established by the U.S. military or unwritten rules about not creating bad press for their employers, some reporters covering the war in Iraq are finding themselves on a short leash.

NBC fired veteran war correspondent Peter Arnett yesterday, saying Arnett was wrong to grant an interview to state-run Iraqi TV in which he said the American-led coalition's initial plan for the war had failed because of Iraq's resistance. Arnett called the interview a "misjudgment" and apologized.

Also yesterday, Fox News Channel's Geraldo Rivera found himself in trouble with the U.S. military on charges of giving away troop movements during a live broadcast. He may be expelled, though his fate was unclear last night.

Last week, free-lance journalist Philip Smucker was ordered to leave Iraq by the U.S. military after being accused of revealing too much information about troop locations during an interview on CNN. Smucker, who was not among the embedded reporters, was in the region covering the war for The Christian Science Monitor. In the past, he has written for the Post-Gazette.

There are some 600 reporters from news organizations who have been placed with specific units for the war; they travel with their units and report on their activities.

The Defense Department's detailed rules for embedded journalists allows embargoes to be imposed on news reports "to protect operation security" and says "date, time or location of previous conventional military missions and actions, as well as mission results, are releasable only if described in general terms."

The Defense Department rules prohibit embedded reporters from revealing some specifics, including geographic locations of military units, information regarding future operations, photography showing level of security at military installations or encampments and information identifying postponed or canceled operations.

Barbara Levin, director of communications for NBC News, said reporters can feed stories anytime they are not moving or their safety is not in jeopardy.

"If it's the middle of the night and they're involved in a mission and we would need to turn on camera lights to feed a story back, that would obviously endanger the safety of the soldiers," she said. "Beyond that, our reporters have had a very successful time in terms of feeding stories back and reporting what they see."

Giving away locations is also foremost in the minds of embedded reporters. "They use general terms like, 'We're in southcentral Iraq.' It doesn't identify the city," Levin said.

On its Web site, CNN posted an editor's note: "CNN's policy is to not report information that puts operational security at risk."

Kathryn Kross, CNN vice president and Washington bureau chief, said the Pentagon's concerns to be "absolutely reasonable in terms of operational security"

"If you're embedded with the troops, you not only want to [not jeopardize safety or operational security] for all the right reasons, but if you're with them, you'd be compromised, too."

Another concern is making sure families don't learn about the fate of loved ones in real time.

"It's been a remarkably smooth process," Kross said. "I think it's a fairly impressive thing the Pentagon has been able to pull off here."

For its part, the Pentagon has mixed feelings about how the process is working.

Some Pentagon leaders have begun to regret the unprecedented access they have granted war correspondents, The Washington Post reported. In recent days, the fundamental problem has been squaring depictions from inside Iraq of pitched battles, guerrilla warfare and hungry soldiers with the upbeat assessments of the war effort issued from the Pentagon and Central Command at Doha, Qatar.

Embedded journalists may be satisfied, but war coverage hasn't gone smoothly for everyone.

The New Zealand-born Arnett, on NBC's "Today" show yesterday, said he was sorry for his statement on Iraqi TV, but added, "I said over the weekend what we all know about the war."

NBC defended him Sunday, saying he had given the interview as a professional courtesy and that his remarks were analytical in nature. But by yesterday morning, the network had switched course, saying it would no longer work with him.

Arnett, who won a Pulitzer Prize reporting in Vietnam for The Associated Press, also gained prominence from covering the 1991 Gulf War for CNN.

One of the few American television reporters left in Baghdad, his reports were frequently aired on NBC and its cable sisters, MSNBC and CNBC.

Leaving a second network under a cloud may mark the end of his TV career. Arnett was the on-air reporter in the 1998 CNN report that accused American forces of using sarin nerve gas on a Laotian village in 1970 to kill U.S. defectors. Two CNN employees were fired and Arnett was reprimanded over the report, which the station later retracted. Arnett left the network when his contract was not renewed.

He went to Iraq this year not as an NBC News reporter but as an employee of the MSNBC show "National Geographic Explorer." When other NBC reporters left Baghdad for safety reasons, the network began airing his reports. NBC said yesterday that he won't be reporting for "National Geographic Explorer," either. Britain's Daily Mirror newspaper said yesterday it had hired Arnett.

Separately, the Pentagon was expected to make a decision late yesterday over whether to expel Fox News' Geraldo Rivera from Iraq for "jeopardizing operational security." Rivera had been reporting on the 101st Airborne Division near Baghdad when he drew a map in the sand in which he reportedly revealed how the attack of Baghdad would unfold.